Our new 135mm wheel for 300 engines delivers up to 18 psi of boost pressure producing arm wrenching acceleration and increased top speed. High performance billet impeller & 3mm spacer increase horsepower through superior impeller blade design and larger interior housing volume. Lightweight billet impeller features a sophisticated blade design that is precision balanced to deliver smooth acceleration. Spacer & impeller install quickly and easily onto stock supercharger base plate.